Silver German (?) spoon with unknown marks

I have got a silver tea spoon with marks I cannot recognize:
The marks are: a cross(?) with the number 12 at its base, and letters RW (within rectangle) and E.
I believe 12 stands for the 12 loth silver, so the origin is probably Germany/Prussia before 1886 or some other central Europe country.
Any idea what it is?
Any help will be greatly appreciated.